CONVERSION OF FLOATING-POINT NUMBERS TO THEIR BINARY EQUIVALENT AND VICE-VERSA

BINARY TO DECIMAL CONVERSION

For the conversion of the floating point binary numbers into their decimal equivalent we use the following rules:

1. The integral part of the floating point number is converted into the decimal equivalent using the usual positional weight notation. The following figure clearly explains this thing:-
   
2. The conversion of the fractional part of the number into its decimal equivalent can be summarized in the following table.

Binary	Decimal Fraction	Decimal Value
.1	1/2	.5
.01	1/4	.25
.001	1/8	.125
.0001	1/16	.0625
.00001	1/32	.03125

DECIMAL TO BINARY CONVERSION

Simple conversion of simple integral part of any decimal can be portrayed as follows:- 

The following figure explains the rule for conversion of fractional part of decimal number to binary equivalent:-

I hope, by reading the above article, you are clear with both types of conversions at their worst scenario, that is when the number to be converted includes fractional part.

Now, after giving a detailed description of conversion, I would like the user to have a look at my source code in C that performs all the above specified conversions. My source code contains two functions that easily perform the following two conversions:-

• Binary to decimal
• Decimal to binary 

The user can give the input as per his/her wish including the floating point numbers.

SOURCE CODE

/********************************************************************************/

#include<stdio.h>

#include<conio.h>

#include<math.h>

#define max 30

int fraction[max],integer[max];

void d2b();

void b2d();

int main()

{

int i,cnum,ch;

float num,f;

clrscr();

while(1)

{

printf("YOU HAVE FOLLOWING CHOICES : \n");

printf("1.CONVERT DECIMAL TO BINARY\n");

printf("2.CONVERT BINARY TO DECIMAL\n");

printf("3.EXIT\n\n");

printf("ENTER YOUR CHOICE : ");

scanf("%d",&ch);

printf("\n");

switch(ch)

{

case 1:

d2b();

break;

case 2:

b2d();

break;

case 3:

exit(1);

default:

printf("YOU HAVE ENTERED A WRONG CHOICE\n");

}

printf("\nPRESS ANY KEY TO CONTINUE...\n");

getch();

clrscr();

}

getch();

return 1;

}

void d2b()

{

float num,f;

int i,cnum,tag;

printf("ENTER ANY DECIMAL NUMBER : ");

scanf("%f",&num);

printf("\n");

f=num-(int)num;

for(i=0;i<max;i++)

{

f=f-(int)f;

fraction[i]=(int)(f*2);

f*=2;

}

cnum=(int)num;

for(i=max-1;i>=0;i--)

{

if(cnum%2==0)

{

integer[i]=0;

}

else

integer[i]=1;

cnum/=2;

}

printf("BINARY EQUIVALENT = ");

tag=0;

for(i=0;i<max;i++)

{

if(integer[i]||tag)

{

tag=1;

printf("%d",integer[i]);

}

}

printf(".");

for(i=0;i<7;i++)

printf("%d",fraction[i]);

printf("\n");

}

void b2d()

{

double num,fnum,result=0;

long inum,i=0,a=0;

printf("ENTER ANY BINARY NUMBER : ");

scanf("%lf",&num);

printf("\n");

inum=num;

fnum=num-(long)num;

printf("%ld\t%lf\n",inum,fnum);

while(inum)

{

result+=(inum%10)*pow(2,i++);

inum/=10;

}

for(i=0;i<max;i++)

{

a--;

fnum*=10;

if(fnum>=1)

{

fnum-=1;

result+=pow(2,a);

}

}

printf("DECIMAL EQUIVALENT = %lf\n",result);

}

/******************************************************************************/

OUTPUT